Xenopus marginal coil ( Xmc), a novel FGF inducible cytosolic coiled-coil protein regulating gastrulation movements

• Published in: Mechanisms of development 2002-04, Vol.113 (1), p.3-14
• Main Authors: Frazzetto, Giovanni, Klingbeil, Pamela, Bouwmeester, Tewis
• Format: Article
• Language: English
• Subjects: Animals; Cell Membrane - metabolism; Coiled coil; Convergent extension; Cytoplasm - metabolism; FGF signaling; Fibroblast Growth Factors - metabolism; Gastrula - physiology; Gastrulation; Gene Expression Regulation, Developmental; Gene Library; Membrane Proteins - biosynthesis; Membrane Proteins - chemistry; Membrane Proteins - genetics; Mesoderm - physiology; Microscopy, Fluorescence; Models, Genetic; Plasmids - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Time Factors; Xenopus; Xenopus laevis; Xenopus Proteins - biosynthesis; Xenopus Proteins - chemistry; Xenopus Proteins - genetics
• ISSN: 0925-4773; 1872-6356
• DOI: 10.1016/S0925-4773(01)00664-5

Gastrulation in vertebrates is a highly dynamic process driven by convergent extension movements of internal mesodermal cells, under the regulatory activity of the Spemann–Mangold or gastrula organizer. In a large-scale screen for genes expressed in the organizer, we have isolated a novel gene, termed Xmc, an acronym for Xenopus marginal coil. Xmc encodes a protein containing two widely spaced evolutionarily non-conserved coiled coils. Xmc protein is found in vesicular aggregates in the cytoplasm and associated with the inner plasma membrane. We show that Xmc is expressed in a dynamic fashion around the blastoporal circumference, in mesodermal cells undergoing morphogenetic movements, in a pattern similar to FGF target genes. Likewise, Xmc expression can be induced by ectopic XeFGF signaling and the early mesodermal expression is dependent on FGF receptor-mediated signaling. Morpholino-mediated translational ‘knock-down’ of Xmc results in embryos that display a reduced elongation of the antero-posterior axis and in a pronounced inhibition of morphogenetic movements in embryos and dorsal marginal zone explants. Xmc loss-of-function does not interfere with mesoderm induction or maintenance per se. Our results suggest that Xmc is a novel FGF target gene that is required for morphogenetic movements during gastrulation in Xenopus.